Steroidal carbinols containing an ethynyl or acetylene group are important components of a number of oral contraceptives available in the market place. The usual method to manufacture these derivatives involves reaction of acetylene gas with steroidal ketones in the presence of base. Another available method is addition of lithium acetylide to the corresponding steroidal ketones. However, one disadvantage of this reagent is that it readily disproportionates into dilithium acetylide and acetylene. This reagent may be stabilized using an amine, for example, ethylenediamine. However, the resulting complex, lithium acetylide diamine, is much less reactive than the amine-free lithium acetylide. Other disadvantages include use of gaseous acetylene, and a large excess of reagent needed for the completion of reaction.
An object of the present invention is to provide a novel method to generate an organometallic reagent and its use to synthesize acetylenic carbinols.